Old New Faces
by SpellStorm
Summary: "Okayyyyy," Isabelle said in a low voice, "When did Brother Zachariah get hot?" Based of this spoiler snippet from CoHF. Magnus has refused remain involved with the Nephilim, but he does contact someone who can help. Two-shot.


**This is based off of Snippet #10 for **_**City of Heavenly Fire**_**: **"Okayyyyy," Isabelle said in a low voice, "When did Brother Zachariah get hot?" **Since I have read **_**The Infernal Devices**_** and therefore know who Brother Zachariah is, I figured I'd venture a guess as to what happens and what Izzy's talking about. Enjoy!**

**BTW, this is pretty much unedited. I kinda finished and uploaded. Sorry for any mistakes!**

* * *

Clary shivered. The air was cold already, and the chilly night breeze that swept through the trees wasn't helping. The rustling of leaves and the breathing of the Shadowhunters were the only sounds to be heard.

"Why are we here again?" she asked, her hushed voice breaking through the silence.

Jace was just as quiet when he answered. "Magnus told me he isn't going to help us anymore, but he could contact someone who might. He said Brother Zachariah would meet us here tonight."

"It's freezing out here," Izzy complained.

"It's the middle of the night, Isabelle. And it doesn't really help that you're holding hands with a Child of the Night."

Isabelle glared at her brother. "Shut up, Alec. I'll hold Simon's hand if I want to." She made a show of tightening her grip on the vampire's fingers.

Jace groaned softly. "Would you two please be quiet? Now is not the time for your ridiculous sibling banter."

The group of five grew silent again. Finally, as the time on Clary's watch read eleven-thirty, a sound came from the trees. Everyone tensed, reaching for their various concealed weapons, adapting fighting stances.

"Brother Zachariah?" Jace said aloud.

A chuckle reached them. "I suppose that's one name for me."

The voice had come from behind them. They all spun around quickly and stared.

"Okayyyyy," Isabelle said in a low voice, "When did Brother Zachariah get hot?"

"_Isabelle!_" Alec hissed, but Clary – though she loved Jace more than anything – had to agree.

Stepping from the shadows was a tall, slender young man. His hair was pitch black, and his slightly curved, dark brown eyes managed not to look threatening. He was, indeed, a very handsome person.

That distinct English accent didn't hurt, either.

The man smiled at their reactions. "I apologize for startling you; I didn't know the best way to announce myself and decided to just wing it." He stepped forward and held out his hand to Jace. "James Carstairs, formerly known you all as Brother Zachariah. You can call me Jem."

Jace stared at Jem's hand for a moment before shaking it. "You can talk."

Jem nodded. "My time with the Brotherhood has come to an end, but we can discuss that later. You're probably cold and tired; come with me." He walked back into the trees.

After a moment of hesitation, Jace shrugged and moved to follow the black-haired man. The other four teens took that as an okay and hurried after them.

* * *

Jem took them to a small, two-story house in a different clearing. Despite the time of night, most of the windows let light spill into the yard. Clary saw the former Silent Brother smile slightly and shake his head before leading the group inside.

"Take a seat," he said, gesturing to a round wooden table in the kitchen. "Is anyone thirsty? I can make tea, coffee, hot chocolate…."

"Hot chocolate, please," Clary requested.

"Tea for me," Alec added.

Izzy and Jace opted for coffee, while Simon remained quiet. Clary could see that his brown eyes were tinted faintly with red, but she knew he was in control of his hunger. He would be fine for another few hours at least.

No one spoke while the drinks were being made. When they were finished, Jem divvied them out. Simon looked surprised when a big mug was placed in front of him.

"It's hot chocolate mixed with deer blood," Jem explained. "It may be a bit cold, but the chocolate should warm it up."

Simon nodded in thanks and took a sip. "It's good."

"Should we be worried that you just so happen to have deer blood in your refrigerator?" Isabelle asked.

"When Magnus told me that you needed help and Jace would be waiting for me, I knew Clary would automatically tag along, and Alec wouldn't let his _parabatai_ come alone, and Isabelle would refuse to be left behind. Naturally I just assumed you would bring Simon as well, so I went out this morning and looked for animal carcasses. I didn't get as much as I'd hoped, but I could only find one deer."

"It's fine, this'll be enough." Already Simon was looking better. He continued to sip his cocoa as the others started on their own drinks.

Jem leaned against the counter and watched them. "As you might've already guessed, I'm not the person Magnus was talking about when he said he knew someone who might be able to help you. Now that I've been released from the Brotherhood, I have no more power than the average Shadowhunter. However, before you meet Magnus' friend, there are some rules that need to be established."

That got everyone's attention. They all turned to look at him. In his eyes, Clary could see a hundred emotions fighting for dominance, but foremost was seriousness. She got a sense that this person meant something to him.

"First rule: you are free to explain your situation and ask for assistance, but there is no obligation to help. What I'm suspecting you'll ask for…. It's difficult and sometimes dangerous. It could even be deadly.

"Rule number two: the things you hear tonight must remain in this house. You may relay any information pertaining to the situation to the Clave, but anything else must not leave here.

"And the last thing: I decide when enough is enough. All of this can be overwhelming. If I say it's time, you must agree to leave. Understood?"

The rules had piqued their curiosity, and they quickly nodded their agreement.

Jem let out a breath. "Alright, then. I'll be back."

He pushed himself off the counter to leave, but before he could, a door opened upstairs. Seconds later a figure ascended the stairs. Halfway down, Clary realized it was a woman. She had long brown hair that flowed down her back in waves. Her skin was slightly tanned and almost completely unmarked. She wore a white dress ending at her knees; a green pendant made of some kind of green stone rested in the center of her collarbone.

Clary saw the way Jem's face lit up when he saw the woman. He posture relaxed almost immediately, and his smile was brighter, his eyes less burdened. This was very obviously someone who meant a lot to him.

"I heard voices," the woman said as she reached to bottom of the stairs. She sounded young, and looked it, too. Her face still held the softness of an adolescent.

Jem automatically looked guilty. "I'm sorry, _Ài_. I didn't even think that you might be asleep. Did we wake you?"

She smiled at him. "It's fine, Jem, I wasn't sleeping. After Magnus' call this morning, I made sure to take a nap so I wouldn't be tired."

"_That's_ what you were doing? I figured you were curled up with a book. No wonder you didn't come downstairs this afternoon; you always come when I play."

She looked disappointed. "I missed your playing?"

Jem took her hands. "No matter; I'll play for you later."

He suddenly seemed to remember the five teenagers at his table. He cleared his throat.

"_Qíngrén_, there are some people you should meet."

He seemed to be saying something to her with his eyes, or at least trying to. Clary wondered if it had anything to do with the fact that this whole time her back had been turned to them.

After several moments, the woman turned around. When she saw them, she stood stock-still, just looking. Her eyes – a mixture of blue and gray, as if they couldn't decide what to be – were wide as she took in the ragtag group. Jem stood behind her, one hand outstretched as if to provide a safety net in case her legs gave out. His entire being radiated caution and worry, but also relief. Clearly he'd been expecting a much worse reaction.

Finally the woman blinked, her body relaxing a fraction. Clary saw Jem let out a small breath and figured it meant crisis averted.

"Hello," she said, her voice small.

Jem stepped up beside her and grasped her right hand. "_Wǒ de ài_, I would like you to meet Alec, Isabelle, Clary, Simon, and Jace. Children, meet my fiancé and Magnus' closest and longest friend, Tessa." It did not go unnoticed that he refrained from using any last names.

Suddenly Clary recognized those eyes. "That's where I've seen you!" she exclaimed. "You were at the party in Alicante after the Battle of Brocelind Plain. You and Magnus were talking, but you left when he came to join us."

Tessa smiled. "Yes, that was me. I hadn't planned on staying long; I just wanted to warn Magnus that I'd seen Camille Belcourt. After successfully avoiding her for 133 years, I figured he wouldn't want to be caught off-guard." She shook her head, seemingly to bring herself out of her memory. "Anyway, that's not why you came here. Magnus told me you needed help in your fight against that demon-blooded Morgenstern. There's something I can try, but I don't know how well it will work. I can't promise anything."

"Whatever you can do, it would be greatly appreciated," Jace said.

Tessa's eyes flashed when Jace spoke, but it was gone the next second. "Then follow me." And without another word, she left the room.

Tessa led them into the living room, where a fire was already roaring in the fireplace. She automatically took a seat in one of the chairs. After gesturing for the others to have a seat, Jem sat next to Tessa on the arm of her chair.

There was a moment of quiet in which the Shadowhunters and the vampire found places to sit. Clary and Jace ended up on the loveseat, while Alec, Isabelle, and Simon took the couch. When they were settled, Tessa began to speak.

"I told you I would help any way I can, and I will, but first you need to know why Magnus sent you to me instead of some other warlock. Someone else would have been more convenient, but I have an ability that no one else does. There's a long explanation as to why, but I won't put you through that. All I'm going to say is that my ability is a bit draining, and can even be somewhat dangerous, under certain circumstances.

"That being said, Magnus told me he told you to bring something that belongs to the Morgenstern boy. Did you?"

Clary reached into her bag and withdrew a silver metal box engraved with the initials _J.C._

"This was my mother's, but Seb- Jonathan took it. It should have a connection with him, anyway; it was a gift to him when he was born."

Tessa took the box gently and studied it for a moment.

"Alright," she said, looking at the group. "Don't freak out."

Then she closed her eyes and breathed deeply.

Several moments of silence passed as the teens watched the warlock intently, wondering what she could do and if she was doing it already. Out of nowhere, Tessa gasped loudly and began to shake. Her skin seemed to ripple, as if trying to shed itself. Clary was alarmed, but it must have been at least semi-normal, for Jem was already laying a blanket over his fiancé's shivering body.

And then it stopped, and they all shouted in alarm. It was no longer Tessa they were looking at. Sitting in the armchair was Sebastian.

Jace's face hardened. He started to get up, but hesitated when he heard Jem speak.

"Do not be alarmed. It is not him; this is Tessa's ability. She can transform herself into another person as long as she has something of theirs. We can explain later, but now you must ask your questions. There's not much time."

It was true. Already the change was showing, skin rippling, hair changing from pale blond to dark brown.

"Where is he?" Alec demanded, wasting no time. "What are his plans?"

But the change was already too far. The warlock had just enough time to gasp out "_Lindau_" before fainting, her body back to normal.

No one spoke while they waited for Tessa to wake up. When she did, she blinked groggily and wrapped the blanket tighter around her body.

"I'm sorry," she whispered. "I couldn't take any more. It was all I could do to keep his form for even a minute. There's so much darkness and hatred in him…." She shuddered. "He is in Lindau, though. I know that much. It's a very small village in Germany. I don't know what he's doing there, but it felt terrible."

Jem wrapped his arms around her. "It's alright, Tessa. You did well."

As Tessa reached up to embrace the former Silent Brother, Clary noticed flashes of black on what she'd thought to be unmarked wrists. She kept the question to herself until Jem left to fetch Tessa a cup of tea.

"What's on your arms?" Clary blurted without thinking.

Tessa looked surprised but not upset. She smiled. "Tattoos." Clary must have looked shocked, because the warlock laughed. "I know, it's not very ladylike. I surprised myself when I got them; I was born in 1862 and was raised a lady. But the times were changing and I decided I had to change with them, so one night I went out and got these done."

She held out both her arms for inspection. On one, the words were written in flowing, dark blue ink; on the other, the ink was silver, and the words had Chinese characters underneath them.

"What do they say?" Isabelle asked, tilting her head.

Tessa smiled. "The left one is Jem's full name, James Carstairs, and underneath are the characters for his other name, Ke Jian Ming. His mother was Chinese," she added, seeing everyone's confused expressions. "The one on the right is my late husband's Welsh name, Gwilym Owain Herondale."

Jace's face paled. "Did you say Herondale?"

Tessa nodded. "Yes; his father married a mundane, a Welsh woman, but his surname remained a Shadowhunter one. Why?"

Jace looked sick. "Because my last name is Herondale."

* * *

**Aaaaand I decided to leave it there. Yes, I know, it's a cliff-hanger, but I figured this was long enough for a single one-shot. Of course, you might want to know what happens next….**

…**.Which is why I decided to make this a two-shot. Not sure when part two will be up, but I'm workin on it.**

**Translations (instead of putting in Chinese characters, I used the words. All translations found on Google Translate):**

_Ài ... _love**  
**

_Qíngrén_ ... sweetheart

_Wǒ de ài _... my love**  
**

**Thanks for reading! Review, maybe?**

**P.S. My other crossover one-shot of these fandoms, **_**History**_**, is becoming a two-shot as well. Keep an eye out for part two!**


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